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Crattelet J, Ghnimi S, Debreyne P, Zaid I, Boukabache A, Esteve D, Auret L, Fillaudeau L. On-line local thermal pulse analysis sensor to monitor fouling and cleaning: Application to dairy product pasteurisation with an ohmic cell jet heater. J FOOD ENG 2013. [DOI: 10.1016/j.jfoodeng.2013.05.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Mejhert N, Wilfling F, Esteve D, Galitzky J, Pellegrinelli V, Kolditz CI, Viguerie N, Tordjman J, Näslund E, Trayhurn P, Lacasa D, Dahlman I, Stich V, Lång P, Langin D, Bouloumié A, Clément K, Rydén M. Semaphorin 3C is a novel adipokine linked to extracellular matrix composition. Diabetologia 2013; 56:1792-801. [PMID: 23666167 DOI: 10.1007/s00125-013-2931-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 04/18/2013] [Indexed: 01/09/2023]
Abstract
AIMS/HYPOTHESIS Alterations in white adipose tissue (WAT) function, including changes in protein (adipokine) secretion and extracellular matrix (ECM) composition, promote an insulin-resistant state. We set out to identify novel adipokines regulated by body fat mass in human subcutaneous WAT with potential roles in adipose function. METHODS Adipose transcriptome data and secretome profiles from conditions with increased/decreased WAT mass were combined. WAT donors were predominantly women. In vitro effects were assessed using recombinant protein. Results were confirmed by quantitative PCR/ELISA, metabolic assays and immunochemistry in human WAT and adipocytes. RESULTS We identified a hitherto uncharacterised adipokine, semaphorin 3C (SEMA3C), the expression of which correlated significantly with body weight, insulin resistance (HOMA of insulin resistance [HOMAIR], and the rate constant for the insulin tolerance test [KITT]) and adipose tissue morphology (hypertrophy vs hyperplasia). SEMA3C was primarily found in mature adipocytes and had no direct effect on human adipocyte differentiation, lipolysis, glucose transport or the expression of β-oxidation genes. This could in part be explained by the significant downregulation of its cognate receptors during adipogenesis. In contrast, in pre-adipocytes, SEMA3C increased the production/secretion of several ECM components (fibronectin, elastin and collagen I) and matricellular factors (connective tissue growth factor, IL6 and transforming growth factor-β1). Furthermore, the expression of SEMA3C in human WAT correlated positively with the degree of fibrosis in WAT. CONCLUSIONS/INTERPRETATION SEMA3C is a novel adipokine regulated by weight changes. The correlation with WAT hypertrophy and fibrosis in vivo, as well as its effects on ECM production in human pre-adipocytes in vitro, together suggest that SEMA3C constitutes an adipocyte-derived paracrine signal that influences ECM composition and may play a pathophysiological role in human WAT.
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Ong FR, Boissonneault M, Mallet F, Doherty AC, Blais A, Vion D, Esteve D, Bertet P. Quantum heating of a nonlinear resonator probed by a superconducting qubit. PHYSICAL REVIEW LETTERS 2013; 110:047001. [PMID: 25166193 DOI: 10.1103/physrevlett.110.047001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Indexed: 06/03/2023]
Abstract
We measure the quantum fluctuations of a pumped nonlinear resonator using a superconducting artificial atom as an in situ probe. The qubit excitation spectrum gives access to the frequency and amount of excitation of the intracavity field fluctuations, from which we infer its effective temperature. These quantities are found to be in agreement with theoretical predictions; in particular, we experimentally observe the phenomenon of quantum heating.
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Bourennane W, Charlon Y, Bettahar F, Chan M, Esteve D, Campo E. Ambient Intelligence for Monitoring Alzheimer Patients. INTERNATIONAL JOURNAL OF E-HEALTH AND MEDICAL COMMUNICATIONS 2013. [DOI: 10.4018/jehmc.2013010103] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Distributed sensors allow people to be followed in independent living situations. In this paper, the authors present a multisensor system which allows monitoring elderly people in hospital environment. The system is composed of motion infrared sensors installed in the ceiling, presence sensor in bed and ZigBee tags embedded on the person. From data collected on locations and movements of people, the system determines, through learning, the behavior model and lifestyle. Analysis and decision algorithm in integrated systems provide the functionality to choose actions in order to alert surveillance team and help them by providing historical events record. A web application is also set up to display results of data processing allowing caregivers to monitor patient behavior. Here, they present the system architecture, the technology used, and some preliminary results.
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Goujon Y, Baron B, Esteve D, Faye MJ, Minaro L, Pommereau P, Rindel D, Talavera MP, Pommereau A. Surveillance des biomarqueurs d’atteinte rénale des salariés exposés à un agent chimique néphrotoxique : étude de faisabilité. ARCH MAL PROF ENVIRO 2012. [DOI: 10.1016/j.admp.2012.03.258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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31
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Dewes A, Ong FR, Schmitt V, Lauro R, Boulant N, Bertet P, Vion D, Esteve D. Characterization of a two-transmon processor with individual single-shot qubit readout. PHYSICAL REVIEW LETTERS 2012; 108:057002. [PMID: 22400953 DOI: 10.1103/physrevlett.108.057002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Indexed: 05/31/2023]
Abstract
We report the characterization of a two-qubit processor implemented with two capacitively coupled tunable superconducting qubits of the transmon type, each qubit having its own nondestructive single-shot readout. The fixed capacitive coupling yields the sqrt[iSWAP] two-qubit gate for a suitable interaction time. We reconstruct by state tomography the coherent dynamics of the two-bit register as a function of the interaction time, observe a violation of the Bell inequality by 22 standard deviations after correcting readout errors, and measure by quantum process tomography a gate fidelity of 90%.
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Kubo Y, Grezes C, Dewes A, Umeda T, Isoya J, Sumiya H, Morishita N, Abe H, Onoda S, Ohshima T, Jacques V, Dréau A, Roch JF, Diniz I, Auffeves A, Vion D, Esteve D, Bertet P. Hybrid quantum circuit with a superconducting qubit coupled to a spin ensemble. PHYSICAL REVIEW LETTERS 2011; 107:220501. [PMID: 22182018 DOI: 10.1103/physrevlett.107.220501] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Indexed: 05/31/2023]
Abstract
We report the experimental realization of a hybrid quantum circuit combining a superconducting qubit and an ensemble of electronic spins. The qubit, of the transmon type, is coherently coupled to the spin ensemble consisting of nitrogen-vacancy centers in a diamond crystal via a frequency-tunable superconducting resonator acting as a quantum bus. Using this circuit, we prepare a superposition of the qubit states that we store into collective excitations of the spin ensemble and retrieve back into the qubit later on. These results constitute a proof of concept of spin-ensemble based quantum memory for superconducting qubits.
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Zgirski M, Bretheau L, Le Masne Q, Pothier H, Esteve D, Urbina C. Evidence for long-lived quasiparticles trapped in superconducting point contacts. PHYSICAL REVIEW LETTERS 2011; 106:257003. [PMID: 21770665 DOI: 10.1103/physrevlett.106.257003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Indexed: 05/31/2023]
Abstract
We have observed that the supercurrent across phase-biased, highly transmitting atomic size contacts is strongly reduced within a broad phase interval around π. We attribute this effect to quasiparticle trapping in one of the discrete subgap Andreev bound states formed at the contact. Trapping occurs essentially when the Andreev energy is smaller than half the superconducting gap Δ, a situation in which the lifetime of trapped quasiparticles is found to exceed 100 μs. The origin of this sharp energy threshold is presently not understood.
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Hofheinz M, Portier F, Baudouin Q, Joyez P, Vion D, Bertet P, Roche P, Esteve D. Bright side of the Coulomb blockade. PHYSICAL REVIEW LETTERS 2011; 106:217005. [PMID: 21699333 DOI: 10.1103/physrevlett.106.217005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2011] [Indexed: 05/31/2023]
Abstract
We explore the photonic (bright) side of the dynamical Coulomb blockade (DCB) by measuring the radiation emitted by a dc voltage-biased Josephson junction embedded in a microwave resonator. In this regime Cooper pair tunneling is inelastic and associated with the transfer of an energy 2eV into the resonator modes. We have measured simultaneously the Cooper pair current and the photon emission rate at the resonance frequency of the resonator. Our results show two regimes, in which each tunneling Cooper pair emits either one or two photons into the resonator. The spectral properties of the emitted radiation are accounted for by an extension to DCB theory.
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Ong FR, Boissonneault M, Mallet F, Palacios-Laloy A, Dewes A, Doherty AC, Blais A, Bertet P, Vion D, Esteve D. Circuit QED with a nonlinear resonator: ac-Stark shift and dephasing. PHYSICAL REVIEW LETTERS 2011; 106:167002. [PMID: 21599402 DOI: 10.1103/physrevlett.106.167002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Indexed: 05/30/2023]
Abstract
We have performed spectroscopic measurements of a superconducting qubit dispersively coupled to a nonlinear resonator driven by a pump microwave field. Measurements of the qubit frequency shift provide a sensitive probe of the intracavity field, yielding a precise characterization of the resonator nonlinearity. The qubit linewidth has a complex dependence on the pump frequency and amplitude, which is correlated with the gain of the nonlinear resonator operated as a small-signal amplifier. The corresponding dephasing rate is found to be close to the quantum limit in the low-gain limit of the amplifier.
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Campo E, Chan M, Bourennane W, Esteve D. Behaviour monitoring of the elderly by trajectories analysis. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2010; 2010:2230-3. [PMID: 21096792 DOI: 10.1109/iembs.2010.5627371] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
This paper presents a way to keep the elderly autonomous in their daily activities. The principle is to monitor their behaviour and more specifically their trajectories of movement in the living area. Two methods have been developed and compared: supervised and unsupervised classification. Some results from data collected in a long-stay setting are shown. They highlight the possibility of determining normal trajectory classes, and by comparison with the usual situation, to trigger alarms when the trajectories are unusual.
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Kubo Y, Ong FR, Bertet P, Vion D, Jacques V, Zheng D, Dréau A, Roch JF, Auffeves A, Jelezko F, Wrachtrup J, Barthe MF, Bergonzo P, Esteve D. Strong coupling of a spin ensemble to a superconducting resonator. PHYSICAL REVIEW LETTERS 2010; 105:140502. [PMID: 21230818 DOI: 10.1103/physrevlett.105.140502] [Citation(s) in RCA: 144] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Indexed: 05/23/2023]
Abstract
We report the realization of a quantum circuit in which an ensemble of electronic spins is coupled to a frequency tunable superconducting resonator. The spins are nitrogen-vacancy centers in a diamond crystal. The achievement of strong coupling is manifested by the appearance of a vacuum Rabi splitting in the transmission spectrum of the resonator when its frequency is tuned through the nitrogen-vacancy center electron spin resonance.
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Le Masne Q, Pothier H, Birge NO, Urbina C, Esteve D. Asymmetric noise probed with a josephson junction. PHYSICAL REVIEW LETTERS 2009; 102:067002. [PMID: 19257625 DOI: 10.1103/physrevlett.102.067002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2008] [Indexed: 05/27/2023]
Abstract
Fluctuations of the current through a tunnel junction are measured using a Josephson junction. The current noise adds to the bias current of the Josephson junction and affects its switching out of the supercurrent branch. The experiment is carried out in a regime where switching is determined by thermal activation. The variance of the noise results in an elevated effective temperature, whereas the third cumulant, related to its asymmetric character, leads to a difference in the switching rates observed for opposite signs of the current through the tunnel junction. Measurements are compared quantitatively with recent theoretical predictions.
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le Sueur H, Joyez P, Pothier H, Urbina C, Esteve D. Phase controlled superconducting proximity effect probed by tunneling spectroscopy. PHYSICAL REVIEW LETTERS 2008; 100:197002. [PMID: 18518479 DOI: 10.1103/physrevlett.100.197002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Indexed: 05/26/2023]
Abstract
Using a dual-mode STM-AFM microscope operating below 50 mK we measured the local density of states along small normal wires connected at both ends to superconductors with different phases. We observe that a uniform minigap can develop in the whole normal wire and in the superconductors near the interfaces. The minigap depends periodically on the phase difference. The quasiclassical theory of superconductivity applied to a simplified 1D model geometry accounts well for the data.
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Nguyen F, Boulant N, Ithier G, Bertet P, Pothier H, Vion D, Esteve D. Current to frequency conversion in a Josephson circuit. PHYSICAL REVIEW LETTERS 2007; 99:187005. [PMID: 17995431 DOI: 10.1103/physrevlett.99.187005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2007] [Indexed: 05/25/2023]
Abstract
The voltage oscillations which occur in an ideally current-biased Josephson junction were proposed to make a current standard for metrology. We demonstrate similar oscillations in a more complex Josephson circuit derived from the Cooper pair box: the quantronium. When a constant current I is injected in the gate capacitor of this device, oscillations develop at the frequency f(B)=I/2e, with e the electron charge. We detect these oscillations through the sidebands induced at multiples of f(B) in the spectrum of a microwave signal reflected on the circuit, up to currents I exceeding 100 pA. We discuss the potential interest of this current-to-frequency conversion experiment for metrology.
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Della Rocca ML, Chauvin M, Huard B, Pothier H, Esteve D, Urbina C. Measurement of the current-phase relation of superconducting atomic contacts. PHYSICAL REVIEW LETTERS 2007; 99:127005. [PMID: 17930546 DOI: 10.1103/physrevlett.99.127005] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2007] [Indexed: 05/25/2023]
Abstract
We have probed the current-phase relation of an atomic contact placed with a tunnel junction in a small superconducting loop. The measurements are in quantitative agreement with the predictions of a resistively shunted SQUID model in which the Josephson coupling of the contact is calculated using the independently determined transmissions of its conduction channels.
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Chauvin M, vom Stein P, Esteve D, Urbina C, Cuevas JC, Yeyati AL. Crossover from Josephson to multiple Andreev reflection currents in atomic contacts. PHYSICAL REVIEW LETTERS 2007; 99:067008. [PMID: 17930862 DOI: 10.1103/physrevlett.99.067008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2006] [Indexed: 05/25/2023]
Abstract
The basic current-carrying mechanism through a superconducting weak link embedded in a resistive environment undergoes a continuous crossover, as the voltage increases, from Josephson Cooper pair transfer exciting electromagnetic modes in the environment to multiple Andreev reflections leading to the creation of quasiparticles. We corroborate these ideas through measurements of the dc current-voltage characteristics of superconducting atomic contacts containing channels of arbitrary and adjustable transmission. We present a simple model, in the spirit of the classical resistively shunted junction model, that accounts well for the observed characteristics.
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Chauvin M, vom Stein P, Pothier H, Joyez P, Huber ME, Esteve D, Urbina C. Superconducting atomic contacts under microwave irradiation. PHYSICAL REVIEW LETTERS 2006; 97:067006. [PMID: 17026194 DOI: 10.1103/physrevlett.97.067006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2006] [Indexed: 05/12/2023]
Abstract
We have measured the effect of microwave irradiation on the dc current-voltage characteristics of superconducting atomic contacts. The interaction of the external field with the ac supercurrents leads to replicas of the supercurrent peak, the well-known Shapiro resonances. The observation of supplementary fractional resonances for contacts containing highly transmitting conduction channels reveals their nonsinusoidal current-phase relation. The resonances sit on a background current which is itself deeply modified, as a result of photon-assisted multiple Andreev reflections. The results provide firm support for the full quantum theory of transport between two superconductors based on the concept of Andreev bound states.
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Huard B, Anthore A, Birge NO, Pothier H, Esteve D. Effect of magnetic impurities on energy exchange between electrons. PHYSICAL REVIEW LETTERS 2005; 95:036802. [PMID: 16090763 DOI: 10.1103/physrevlett.95.036802] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Indexed: 05/03/2023]
Abstract
In order to probe quantitatively the effect of Kondo impurities on energy exchange between electrons in metals, we have compared measurements on two silver wires with dilute magnetic impurities (manganese) introduced in one of them. The measurement of the temperature dependence of the electron phase coherence time on the wires provides an independent determination of the impurity concentration. Quantitative agreement on the energy exchange rate is found with a theory by Göppert et al. that accounts for Kondo scattering of electrons on spin-1/2 impurities.
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Ithier G, Collin E, Joyez P, Vion D, Esteve D, Ankerhold J, Grabert H. Zener enhancement of quantum tunneling in a two-level superconducting circuit. PHYSICAL REVIEW LETTERS 2005; 94:057004. [PMID: 15783681 DOI: 10.1103/physrevlett.94.057004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2004] [Indexed: 05/24/2023]
Abstract
We have investigated the macroscopic quantum tunneling (MQT) of the phase across a Josephson junction embedded in a superconducting circuit. This system is equivalent to a spin 1/2 particle in a potential energy well. The MQT escape rate of such a particle was recently predicted to be strongly modified when a crossing of its inner Zeeman levels occurs while tunneling. In this regime, we observe a significant enhancement of the MQT rate and compare it to theory.
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Siddiqi I, Vijay R, Pierre F, Wilson CM, Frunzio L, Metcalfe M, Rigetti C, Schoelkopf RJ, Devoret MH, Vion D, Esteve D. Direct observation of dynamical bifurcation between two driven oscillation states of a Josephson junction. PHYSICAL REVIEW LETTERS 2005; 94:027005. [PMID: 15698220 DOI: 10.1103/physrevlett.94.027005] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2003] [Indexed: 05/24/2023]
Abstract
We performed a novel phase-sensitive microwave reflection experiment which directly probes the dynamics of the Josephson plasma resonance in both the linear and the nonlinear regime. When the junction was driven below the plasma frequency into the nonlinear regime, we observed for the first time the transition between two different dynamical states predicted for nonlinear systems. In our experiment, this transition appears as an abrupt change in the reflected signal phase at a critical excitation power. This controlled dynamical switching can form the basis of a sensitive amplifier, in particular, for the readout of superconducting qubits.
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Collin E, Ithier G, Aassime A, Joyez P, Vion D, Esteve D. NMR-like control of a quantum bit superconducting circuit. PHYSICAL REVIEW LETTERS 2004; 93:157005. [PMID: 15524928 DOI: 10.1103/physrevlett.93.157005] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2004] [Indexed: 05/24/2023]
Abstract
Coherent superpositions of quantum states have already been demonstrated in different superconducting circuits based on Josephson junctions. These circuits are now considered for implementing quantum bits. We report on experiments in which the state of a qubit circuit, the quantronium, is efficiently manipulated using methods inspired from nuclear magnetic resonance (NMR): multipulse sequences are used to perform arbitrary operations, to improve their accuracy, and to fight decoherence.
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Van Meer F, Esteve D. Microtechnology applications for medical instrumentation. Cell Mol Biol (Noisy-le-grand) 2004; 50:301-8. [PMID: 15209352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
The recent progresses in microtechnologies open new possibilities in terms of design, cost reductions, improve performances and, moreover, open new fields of applications in surgical instrumentation. Microtechnology techniques will lead to reconsider the design of medical instrumentation. Surgical tools should not be thought as mechanical systems but as surgical components ("surgical chips") designed with micro-technologies and including microsensors/microactuactors.
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Anthore A, Pothier H, Esteve D. Density of states in a superconductor carrying a supercurrent. PHYSICAL REVIEW LETTERS 2003; 90:127001. [PMID: 12688893 DOI: 10.1103/physrevlett.90.127001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2002] [Indexed: 05/24/2023]
Abstract
We have measured the tunneling density of states (DOS) in a superconductor carrying a supercurrent or exposed to an external magnetic field. The pair correlations are weakened by the supercurrent, leading to a modification of the DOS and to a reduction of the gap. As predicted by the theory of superconductivity in diffusive metals, we find that this effect is similar to that of an external magnetic field.
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Anthore A, Pierre F, Pothier H, Esteve D. Magnetic-field-dependent quasiparticle energy relaxation in mesoscopic wires. PHYSICAL REVIEW LETTERS 2003; 90:076806. [PMID: 12633262 DOI: 10.1103/physrevlett.90.076806] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2002] [Indexed: 05/24/2023]
Abstract
In order to find out if magnetic impurities can mediate interactions between quasiparticles in metals, we have measured the effect of a magnetic field B on the energy distribution function f(E) of quasiparticles in two silver wires driven out of equilibrium by a bias voltage U. In a sample showing sharp distributions at B=0, no magnetic field effect is found, whereas, in the other sample, rounded distributions at low magnetic field get sharper as B is increased, with a characteristic field proportional to U. Comparison is made with recent calculations of the effect of magnetic-impurities-mediated interactions taking into account Kondo physics.
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